Remove list dots in the screenshot nav on the home page.

Before:

![screenshot from 2013-09-23 22 05 17](https://f.cloud.github.com/assets/1447206/1197191/7ef839cc-24ce-11e3-8e8e-4a38bd6afcec.png)

After:

![screenshot from 2013-09-23 22 05 30](https://f.cloud.github.com/assets/1447206/1197192/81a4c802-24ce-11e3-8bfb-b812ae1e8946.png)